[ubuntu] Failure to boot into Ubuntu (wubi)

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Hi there
I recently installed ubuntu using wubi. Everything was going fine until I edited my /etc/default/grub file by adding radeon.audio=1 to the GRUB_CMDLINE_LINUX variable because my HDMI sound wasn't working.
When I unplugged the HDMI cable the screen went black and stayed like that. I then restarted my laptop and attempted to boot into ubuntu without success.
Resarting and trying a few times ended with different screens, one was blank, and sometimes I would get into the grub prompt.
I couldn't boot from the grub prompt following these instructions either http://ubuntuforums.org/
(Hardware)